FlexRAN Introduction
The Radio Access Network (RAN) segment has been the final frontier to conquer in the quest for network virtualization of telecom companies. Traditionally, RAN infrastructure components and RAN control applications such as baseband and radio units are built using proprietary hardware and protocols, limiting the opportunities for the ecosystem to evolve into a bigger vendor community. Intel’s FlexRAN reference architecture has transformed how RAN control functions were designed and implemented. FlexRAN reference architecture introduced the disaggregation of RAN software and hardware. This means that the baseband functions such as L1, L2, L3 and transport processing are processed as software by general-purpose processors such as Intel x86 using a Commercial Off-The-Shelf (COTS) computing platform. This was made possible by offloading real-time L1 functions of the baseband unit to a pluggable FPGA card. FlexRAN reference architecture was initially implemented for LTE with control and data plane separation.
In 5G specifications, 3GPP specs paved the way for the disaggregation of baseband units. 5G RAN control offers disaggregation of BBU (Baseband unit), namely: a distributed unit (DU) and a centralized unit (CU). The DU manages the real-time L1 and L2 scheduling operations while the CU oversees the non-real-time, higher L2 and L3.
The RAN segment of the telecom network has been the final frontier to be conquered in the quest for network virtualization.
FlexRAN reference architecture enables vendors to virtualize DU & CU functions and host L2, and L3 functions on general-purpose hardware (COTS hardware).
FlexRAN System and Ecosystem Overview
FlexRAN Reference Architecture consists of Software and Hardware components that enable vendors to implement virtualized DU and CU systems.
For L1 acceleration, there are multiple options. Intel announced the latest 4th generation Xeon-based Intel Architecture called “Sapphire Rapids,” which has an inbuilt capability for L1 acceleration. This avoids the need to have a pluggable external card. “Sapphire Rapids” platform enables vendor eco-system to build RAN infrastructure completely in software without needing additional hardware such as pluggable FPGA. FlexRAN L1 components are compliant with 3GPP specifications 38.211 and 38.212. The latest version of FlexRAN software is Rel-22.11 which was released in December-2022.
FlexRAN Benefits
While other Virtualized Radio Access Network (vRAN) solutions are driven by SoC-based L1 accelerators, FlexRAN is a unique vRAN framework that enables vendors to implement vRAN solutions without proprietary hardware/SoC.
Compared to other vRAN solutions available in the market, FlexRAN provides the following unique benefits:
Proprietary L1 SoC-based vRAN solutions require significant effort for implementation due to the complexities involved in the FAPI interface between L2 and L1 SoC. FlexRAN reference architecture is a flexible architecture that avoids such vendor lock-in and drives innovation. TCO can be optimized significantly compared to the existing proprietary and other vRAN solutions.
HCLTech-Intel partnership to accelerate vRAN & O-RAN transformation
HCLTech is a contributing member of the O-RAN alliance, a leading System integrator and leader in Virtualized network space. HCLTech is making forays into providing enterprises with a flexible cloud-based or on-prem and scalable (Containerized) private network deployment models leveraging Intel’s FlexRAN platform coupled with Intel’s Smart Edge solution to ease the complexity of deploying flexible deployment models from LTE to 5G to CBRS technologies.
From Engineering perspective, HCLTech has been engaged by various FlexRAN partners to accelerate vRAN development and deployment for Vendor and Operator community. HCLTech has invested in ORAN labs for radio integration and validation.
HCLTech partnered with Intel to drive radio access network transformation for the ecosystem. HCLTech owns end-to-end solution development and onboard ecosystem partner network from diverse streams such as Radio, Transmission, Core, SIM Management, Cloud, Infra, Apps, MEC.
HCLTech’s proposition in key areas of radio access network infrastructure transformation is listed in the diagram below:
HCLTech’s POV on typical end-to-end Private Network/OvRAN architecture leveraging Intel components
